I've thought a lot about this, and long wondered why it's such a common feeling in journalism that ads (however speculative and low-quality) are somehow better

I've thought a lot about this, and long wondered why it's such a common feeling in journalism that ads (however speculative and low-quality) are somehow better than things like affiliate links. If someone writes reviews (about lots of books, for example) and all of them have an affiliate link, regardless of whether it's a positive or negative review, and they state clearly, somewhere (rather somewhere on their blog/site than in every link) that they get a percentage of each copy sold, I think that's a good thing. I think they should, and they should tell the reader that if they buy the book via this link, they help support the magazine. Combined with BrandonM's suggestion to steer readers in the "right" direction, and point them to another item instead ("this book wasn't that good, but this book about a similar subject is worth picking up!), that's a nice service which nobody should have to be ashamed about. Of course this suggests that readers have a reason to trust you, but then again (as BrandonM points out): If they don't, why are they reading your review?